public class test04 {
    class Solution {
        public int combinationSum4(int[] nums, int target) {
            //组合：内层物品，外层背包
            //完全背包:正序遍历
            int[] dp = new int[target+1];
            dp[0] = 1;
            for(int j = 0;j<=target;j++){
                for(int i = 0;i<nums.length;i++){
                    if(j>=nums[i]){
                        dp[j] += dp[j-nums[i]];
                    }
                }
            }
            return dp[target];
        }
    }
}
